Soil Nutrition Management for Sustainable Agriculture in Shaanxi

Field experiments were conducted for the major cash crops (grape, apple, and chili pepper) in Fufeng and Heyang, Shaanxi.

Application of phosphorus (P) and potassium (K) increased grape yield by 4 and 12%, respectively. Grape quality was influenced more by K than P fertilizer; specifically vitamin C concentration increased by 3.1 mg/kg and sugar content by 12 to 16%. Balanced use of N, P, and K resulted in higher income and although farmers invested US$114/ha more in fertilizers, their net income improved by US$595/ha.

Apple orchards receiving a balanced NPK treatment had higher N and P concentrations in leaves and longer branches compared to the NP treatment. Although K did not increase apple production, apple quality (lower total acidity, higher vitamin C, increased sugar concentration, and a more attractive color) improved markedly. The fruit were found to be more competitive in the marketplace.

Chili pepper trials indicate that K application reduced nitrate (NO₃^–) concentration and increased vitamin C concentration. Potassium improved both pepper quality and yield. Compared to common farmer practice, chili pepper yields from five demonstration plots averaged 15% more yield with balanced NPK application.

Approximately 500,000 ha of apple orchards, 40,000 ha of chili pepper, and 10,000 ha of grape are grown in Shaanxi. Balanced use of fertilizers will have a great impact on improving farmers’ income and the local economy. Shaanxi-NMS-02